401-943-1164 / US & Canada Toll Free: 877-943-1164

Catalog # 307391 - Model 7391 DB25 A/B Switch, Automatic Fallback & RS232 Remote

    DB25 A/B Switch, Auto Fallback, RS232 RemoteDB25 A/B Switch, Auto Fallback, RS232 RemoteDB25 A/B Switch, Auto Fallback, RS232 Remote
Click image to enlarge
    • DB25 A/B Switch, Auto Fallback, RS232 Remote
    • DB25 A/B Switch, Auto Fallback, RS232 Remote
    • DB25 A/B Switch, Auto Fallback, RS232 Remote
Base Price:
Catalog No: 307391
Model No: 7391
Product Type:Switches: Copper
Cable Type/Port Connector:DB25 Switch Ports
Channels per Switch Chassis:1
Electronic Switches/Power Required:PathWay® Copper
Remote Control:Auto Fallback, RS232 Serial
Auto Fallback:AutoSense, Monitors Port A & Port B
Remote Port:DB9
Local Control:Pushbutton


Shipping Terms

Shipments are made via UPS Ground, unless otherwise specified. Freight charges are prepaid and added to your invoice. We can estimate the freight costs for you.

We can ship freight collect on your account, just provide your UPS Account Number.

We can also ship via the carrier of your choice. Provide the details and your account number.

Products shall be shipped F.O.B. Electro Standards' facility. Title to and risk of loss or damage to the products shall pass to you upon Electro Standards delivery of the products to a carrier for shipment. Title to software will remain with the applicable licensor. Electro Standards' prices do not include shipping and handling charges. Electro Standards reserves the right to use its own discretion in the manner and routing of shipments. Electro Standards shall be permitted to deliver products in separate lots.

Shipping Return Policy

  • To return an item, contact Electro Standards at 401-943-1164 to obtain a Return Material Authorization (RMA) number. RMA numbers are valid for 30 days after the date of the shipment and cannot be extended or re-issued. We are unable to accept returns without an RMA number.
  • All returns except those of defective product are subject to a 15% restocking fee, and additional charges for handling or freight are refunded only in cases of defective products.
  • Return freight must be shipped prepaid. We recommend that you insure the package as you are responsible for risk of loss on all returned packages. We recommend that all cartons are properly packed as Electro Standards is not responsible for product damaged en route. We do not issue call tags for product returns.
  • Returned product must be clean, undamaged, and complete with all manuals, accessories, documents and packaging. The items must be in a resalable condition.
  • The product must have with it a copy of the original invoice or packing slip and the appropriate RMA paperwork.
  • If your item is not working properly, please contact Electro Standards at 401-943-1164 for help in trouble-shooting your application.
  • If the product is defective, Electro Standards will repair or replace that item (at our discretion) upon receipt and evaluation of the original product.
  • Electro Standards reserves the right to authorize product returns after 30 days from the invoice date in some cases. If the product is accepted after 30 days, credit will be issued toward future pruchases only and some additional restocking charges may be applied.
  • All credits from RMAs must be used within one calendar year of issue.

Ask a Question

Protected Document Request


Model 7391 Single Channel DB25 A/B Switch with Automatic Fallback and RS232 Remote Control

  • Can also switch automatically.  You select the trigger signal: RD or DCD


  • PORT CONNECTORS: (3) DB25 female connectors labeled A, B, and Common.
  • FRONT PANEL CONTROL: (1) Manual pushbutton to select switch position and mode of operation to be changed.
  • DISPLAY: (2) Red LED's display switch position and switch mode.
  • and mode of operation.
  • REMOTE CONTROL: (1) DB9(F) connector labeled REMOTE accepts RS232 serial data ASCII commands.
  • POWER:  UL approved 100VAC-240VAC, 50Hz-60 Hz wall mount power module supplies 12 VDC, 500mA to the unit. Has 2-prong, US, non-polarized plug.
  • DIMENSIONS: Rackmount, 19.0" W x 1.75" H x 8.21" D. [18.3 x 4.5 x 20.9 cm]
  • WEIGHT: Approximately 4.4 lbs [2.0 kg] 

PathWay® Model 7391 RS232 DB25 A/B Switch Application

PathWay® Model 7391 DB25 Auto Fallback Application


  • The unit may be switched manually, remotely, or automatically.
  • Front panel pushbutton control.
  • Remote RS232 ASCII commands that allow the user to control switch position, lockout front panel operations, obtain switch status, as well as, query firmware version number, query serial number and enable/disable autosend of switch positions.
  • Automatic switching monitors either RD activity or DCD presence on ports A and B programmed by DIP switch settings.
  • Front panel LED's display present position, power status and operating mode.
  • The switch ports are transparent to all data.
  • All 25 pins of the DB25 interface are switched via break-before-make electromechanical relays.
  • Protective ground Pin 1 is tied together between A, B and COM.
  • Signal ground Pin 7 on A and B are tied to board ground for reference when monitoring signals.
  • The unit maintains last set position on power loss and continues to pass data.
  • When power is restored, unit loads previous position and mode of operation and checks DIP switch settings and Remote port to determine the correct startup configuration.

The PathWay® Model 7391 Single Channel DB25 A/B Switch with Auto Fallback and RS232 Remote allows the user the capability of sharing a single port interface device connected to the “COMMON” port among two other devices connected to the “A” and “B” ports.  The Model 7391 is enclosed in a 1U, full rack size, all metal black chassis designed to provide EMI/RFI shielding and fit in a standard 19” rack.  

The switch may be controlled locally by manually operating the front panel pushbutton or remotely from the DB9 Remote Control port located on the rear of the unit.  The DB9 Remote port provides control through RS232 Serial Commands, and allows the user to both control and monitor the switch position remotely.  The front panel LED display indicates the switch position and unit power status.

When in Automatic Fallback Mode, the unit monitors either RD activity or DCD presence on ports A and B.  If activity or presence is lost on the active port, the unit checks if there is activity or presence on the other port and, in the event that there is activity or presence, the unit switches to the other port.  If there is no activity or presence on either port, the unit will maintain its connection to its present port and continue to monitor both ports.  The user can override Automatic Fallback operation from the front panel or Remote port and force the unit to operate as an A/B switch (Manual Mode).

Option: Wide Range Power Module: (Cat No. 517277) CE, RoHS and UL listed table mount power module, 100VAC-240VAC, 50Hz-60Hz in place of the standard power module that is included with the unit.  Has IEC 60320 C14 inlet.  Ideal for international applications.

TO READ THE ARTICLE: "ADVANCES IN NETWORK SWITCHES" click link to read as a pdf. You need Acrobat Reader to view this file. 

For custom network switches call our friendly customer support staff at 401-943-1164, email eslab@electrostandards.com, or complete our online form: /Products-Custom/Copper-Switch/

Electro Standards can supply all your Network Cable requirements. Click here to reach our CABLES, COPPER NETWORK Webpage.

All data switches, data communication products, and data acquisition products are subject to a one year warranty against manufacturing defects.  The limit of ESL liability is limited to the cost of the ESL product provided.

 *Prices online are subject to change and verification.

All ESL products are available for export.

Available Combo Deals